The American Heart Association says that being physically active is associated with a lower risk of heart disease and diabetes. Researchers have recently documented that exercise is also associated with a reduced appetite, specifically, it reduces the amount of food you eat by about 15 percent.
But which exercise is best to stay slim? Researchers in Copenhagen have now studied how running and training for marathons impacts your waist circumference and waist-to-hip ratio. Not surprisingly, the researchers found that middle-aged women who ran more than six to seven hours a week had smaller waists, as well as a lower waist-to-hip ratio. Middle-aged women who ran for four to five hours a week also had slightly smaller waists than their less active counterparts.
How does running affect your body? Exercise can be beneficial for several reasons: Running boosts mood, increases metabolism, and increases blood flow to the brain, which can support brain function and promote higher blood pressure.
There are some downsides: Running can be physically and mentally exhausting. Addressing depression, anxiety, sleep problems, and other lifestyle problems can take some time, too. Runners can experience some soreness, especially the morning after a race, if the run is too long or if their muscles are used to over-compensating. There can also be side effects: often, runners can become sensitive to nitrates, blood sugars, and blood oxygen levels. Runners who run long distances need to be careful not to eat a lot of carbohydrates before, during, or after a run.
Before you start running, speak to your health care provider, especially if you are considered obese or have a heart condition. Knowing when to begin and when to stop is important to protect your health and to avoid injury.
This article originally appeared on Harvard Health Publications.